Question. I know that concrete can “burn” skin if it's left in contact for too long. Is this a serious problem for homeowners and do-it-yourselfers?
Answer. For an answer, we turned to the world's greatest expert in this subject, Bill Hime at Wiss, Janney, Elstner Associates, who had this impassioned plea:
Fresh concrete can cause chemical “burns” to the homeowner putting in his own crawl space, patio, or driveway. Lifetime injury! And all without any warning or feeling of pain until hours later.
These third-degree chemical burns can occur through porous clothing, such as shirts or trousers. Bare skin actually presents less danger. “Burning” occurs without heat. Skin, flesh, and nerves are destroyed without pain. Only hours later does the pain occur, maybe even the next day.
Why do these “burns” occur? Because fresh portland cement concrete is extremely alkaline-caustic, having a pH perhaps even above the textbook “maximum” of 14-ten times as strong as household drain cleaners.
Having just been hired in my 100th cement-burn case, where the doctors considered arm and leg amputation, perhaps Concrete Construction can provide an avenue for getting the information out. Obviously my numerous technical papers on the subject have not been successful, nor have the National Ready Mixed Concrete Association's and the Portland Cement Association's great efforts.
Injuries usually occur to a homeowner putting in his own concrete. Unfortunately, this sometimes happens under the watchful eye of a ready-mix truck driver who hasn't received the information, or who doesn't bother to caution that “It'll burn you.” No heat is felt, no problem is anticipated. Who would expect that kneeling on concrete could cause such distress?
Please, please, if you are a do-it-yourselfer, protect yourself! Or, if you are a concrete contractor, talking to someone who is planning to do some concrete work or if you sell portland cement or concrete to such a person, warn them, even in attention-getting print. “DANGER—Can cause third-degree chemical ‘burns' without heat or pain sensation.”
I never want another cement-burn case. Help me to not get one.